Mobile station, core network node, base station subsystem, and methods for implementing longer paging cycles in a cellular network

ABSTRACT

A mobile station, a core network node, a base station subsystem, and various methods are described herein for implementing longer paging cycles (longer Discontinuous Reception (DRX) mode) in a cellular network which has a benefit of reducing the energy consumption of the mobile station&#39;s battery.

CLAIM OF PRIORITY

This application claims the benefit of priority to Indian ApplicationNo. 2484/DEL/2013, filed on Aug. 22, 2013, and U.S. ProvisionalApplication No. 61/888,310, filed on Oct. 8, 2013. The entire contentsof each of these applications are hereby incorporated by reference forall purposes.

TECHNICAL FIELD

The present invention relates to a mobile station, a core network node,a base station subsystem, and various methods for implementing longerpaging cycles within a cellular network.

BACKGROUND

The following abbreviations are herewith defined, at least some of whichare referred to within the following description of the prior art andthe present invention.

-   AFC Automatic Frequency Control-   ATC Automatic Time Control-   BA BCCH Allocation-   BCCH Broadcast Control Channel-   BS-PA-MFRMS Base Station Paging Multiframes-   BSIC Base Station Identification Code-   CCCH Common Control Channel-   CRC Cyclic Redundancy Check-   DRX Discontinuous Reception-   E-UTRA Evolved-Universal Terrestrial Radio Access-   FCCH Frequency Correction Channel-   GSM Global System for Mobile Communications-   HLR Home Location Register-   LA Location Area-   MS Mobile Station-   MTC Machine Type Communication-   NAS Non Access Stratum-   RA Routing Area-   RSSI Received Signal Strength Indicator-   SCH Synchronization Channel-   TSC Training Sequence Code-   UTRA Universal Terrestrial Radio Access

In a Global System for Mobile Communications (GSM) network today, eachregistered mobile station (MS) must monitor its own paging group on thepaging channel periodically with a periodicity which varies between 0.47and 2.12 seconds and is set by the parameter BS-PA-MFRMS (see 3GPP TS44.018 V11.3.0 (2012-11)'s chapter 10.5.2.11—the contents of which areincorporated by reference herein). The length of the paging cycle is setto achieve a balance between the acceptable responsiveness for mobileterminated call set-up procedures and the MS battery lifetime. Today,the MS uses a significant amount of power decoding and processingreceived information which is not intended for it when it periodicallychecks for incoming paging messages and performs other idle modeactivities. This leads to significant overhead which quickly drains theMS battery especially for MSs which are characterized as machine typecommunication (MTC) devices.

SUMMARY

A mobile station, a core network node, a base station subsystem, andvarious methods for implementing paging cycles in a cellular network toaddress problems with existing systems are described in the presentapplication. Advantageous embodiments of the mobile station, the corenetwork node, the base station subsystem, and various methods arefurther described in the present application.

In one aspect, a mobile station is configured to implement paging cyclesin a cellular network. The mobile station comprising at least oneprocessor, and at least one memory that stores processor-executableinstructions, wherein the at least one processor interfaces with the atleast one memory to execute the processor-executable instructions,whereby the mobile station is operable to determine if a serving cell inthe cellular network is acceptable to stay camped-on. If the result ofthe determination is that the serving cell is acceptable to staycamped-on, then the mobile station is operable to perform a first typeof synchronizing procedure (short sync up procedure) and attempt to reada radio block (e.g., paging block, CCCH block, paging message, pagingnotification) received per a first DRX mode, wherein the first DRX modehas a longer time period than a legacy second DRX mode. If the result ofthe determination is that the serving cell is not acceptable to staycamped-on or the mobile station is not able to read the received radioblock during the first type of synchronizing procedure, then the mobilestation is operable to perform a second type of synchronizing procedure(long sync up procedure) and attempt to read another radio block,wherein the first type of synchronizing procedure has a shorter durationthan the second type of synchronizing procedure. The mobile stationoperating in this manner has the advantage of reducing the energyconsumption of the mobile station's battery, as compared to a mobilestation operating under a legacy paging cycle.

In another aspect, a method in a mobile station is for implementingpaging cycles in a cellular network. The method comprises the mobilestation determining if a serving cell in the cellular network isacceptable to stay camped-on. If the result of the determination is thatthe serving cell is acceptable to stay camped-on, then the mobilestation performs a first type of synchronizing procedure (short sync upprocedure) and attempts to read a radio block (e.g., paging block, CCCHblock, paging message, paging notification) received per a first DRXmode, wherein the first DRX mode has a longer time period than a legacysecond DRX mode. If the result of the determination is that the servingcell is not acceptable to stay camped-on or the mobile station is notable to read the received radio block during the first type ofsynchronizing procedure, then the mobile station performs a second typeof synchronizing procedure (long sync up procedure) and attempts to readanother radio block, wherein the first type of synchronizing procedurehas a shorter duration than the second type of synchronizing procedure.The method has the advantage of reducing the energy consumption of themobile station's battery since it is expected that for a large majorityof the time, a mobile station will be able to determine that the servingcell is acceptable to stay camped-on and will be able to successfullyread a radio block during the short sync up procedure.

In still another aspect, a base station subsystem (BSS) is configured toimplement paging cycles for a mobile station in a cellular network. TheBSS comprising at least one processor, and at least one memory thatstores processor-executable instructions, wherein the at least oneprocessor interfaces with the at least one memory to execute theprocessor-executable instructions, whereby the BSS is operable toreceive, from a core network node in the cellular network, a messagecontaining information the BSS needs to generate and transmit on a radiointerface a radio block (e.g., paging block, CCCH block, paging message,paging notification) for the mobile station. The BSS is also operable totransmit the radio block according to a first DRX mode rather than alegacy second DRX mode in one or more cells of a paging area of themobile station, wherein the first DRX mode has a longer time period thanthe legacy second DRX mode. The BSS operating in this manner has theadvantage of enabling the possibility of reducing the energy consumptionof the mobile station's battery.

In yet another aspect, a method in a BSS is for implementing pagingcycles for a mobile station in a cellular network. The method comprisesthe BSS receiving, from a core network node in the cellular network, amessage containing information the BSS needs to generate and transmit ona radio interface a radio block (e.g., paging block, CCCH block, pagingmessage, paging notification) for the mobile station. The BSS alsotransmits the radio block according to a first DRX mode rather than alegacy second DRX mode in one or more cells of a paging area of themobile station, wherein the first DRX mode has a longer time period thanthe legacy second DRX mode. The method has the advantage of enabling thepossibility of reducing the energy consumption of the mobile station'sbattery.

In still yet another aspect, a core network node is configured toimplement paging cycles for a mobile station in a cellular network. Thecore network node comprising at least one processor, and at least onememory that stores processor-executable instructions, wherein the atleast one processor interfaces with the at least one memory to executethe processor-executable instructions, whereby the core network node isoperable to identify the mobile station as being configured per a firstDRX mode rather than a legacy second DRX mode, wherein the first DRXmode has a longer time period than the legacy second DRX mode. The corenetwork node is also operable to receive downlink payload for the mobilestation. Upon receipt of the downlink payload, the core network node isoperable to transmit to one or more BSSs which manage cells in a pagingarea of the mobile station a message containing information each BSSneeds to generate and transmit on a radio interface a radio block (e.g.,paging block, CCCH block, paging message, paging notification) for themobile station per the first DRX mode. The core network node operatingin this manner has the advantage of enabling the possibility of reducingthe energy consumption of the mobile station's battery.

In yet another aspect, a method in a core network node is forimplementing paging cycles for a mobile station in a cellular network.The method comprises the core network node identifying the mobilestation as being configured per a first DRX mode rather than a legacysecond DRX mode, wherein the first DRX mode has a longer time periodthan the legacy second DRX mode. The core network node also receivesdownlink payload for the mobile station. Upon receipt of the downlinkpayload, the core network node transmits to one or more BSSs whichmanage cells in a paging area of the mobile station a message containinginformation each BSS needs to generate and transmit on a radio interfacea radio block (e.g., paging block, CCCH block, paging message, pagingnotification) to the mobile station per the first DRX mode. The methodhas the advantage of enabling the possibility of reducing the energyconsumption of the mobile station's battery.

Additional aspects of the invention will be set forth, in part, in thedetailed description, figures and any claims which follow, and in partwill be derived from the detailed description, or can be learned bypractice of the invention. It is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory only and are not restrictive of the inventionas disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be obtainedby reference to the following detailed description when taken inconjunction with the accompanying drawings:

FIG. 1 is a diagram of an exemplary cellular network which is used tohelp describe how a core network node (e.g., SGSN), multiple BSSs, and amobile station (e.g., MTC device) are configured to implement pagingcycles which are longer than in the past in accordance with differentembodiments of the present invention;

FIG. 2 is a flow chart of a method in the mobile station (e.g., MTCdevice) for implementing paging cycles which are longer than in the pastin accordance with the present invention;

FIG. 3 is a flow chart of a method in the mobile station (e.g., MTCdevice) for implementing paging cycles with a longer duration than inthe past in accordance with an embodiment of the present invention;

FIG. 4 is a flow chart of a method in the mobile station (e.g., MTC) forimplementing paging cycles with a longer duration than in the past inaccordance with another embodiment of the present invention;

FIG. 5 is a flow chart of a method in the BSS for implementing pagingcycles with a longer duration than in the past in accordance withdifferent embodiments of the present invention; and

FIG. 6 is a flow chart of a method in the core network node forimplementing paging cycles with a longer duration than in the past inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The existing 3GPP specification assumes that the requirement forreachability of each MS is time critical, i.e., communication has to beinitiated as soon as possible after initial reception of an incomingpaging message (paging block) within the core network. This means thateach MS must spend a significant amount of energy on decodinginformation not intended for it when periodically checking for anincoming page each time its paging block occurs. This prevents aprolonged sleep mode in the MS. For less time critical applications,e.g., for certain types of machine type communication (MTC)applications, this time critical reachability might be unnecessary as asignificant percentage of these types of applications are not expectedto be especially time critical with regards to the downlinkcommunication mechanism being used for payload delivery because thepayload itself is not very time critical. Hence, if the paging groupmonitoring is performed more infrequently by specific types of MSs(e.g., MTC devices) that require less time critical communication, thenless energy would be consumed by these MSs in these cases. The presentapplication addresses the problem of excessive power consumption bythese specific types of MSs in which battery power is a major bottleneckfor their operation (e.g., they may not have access to external power)due to the unnecessary time critical management of downlinkcommunication (i.e., paging group monitoring) by not requiring a timecritical paging mechanism for cases where the fast delivery of downlinkpayload is not necessary. In other words, the disclosed techniquesreduce energy consumption of these specific types of MSs while in idlemode, which leads to a significant decrease in the rate that the batterypower in the MSs is drained. A detailed discussion regarding thesetechniques in various embodiments is provided below with respect toFIGS. 1-6.

Referring to FIG. 1, there is a diagram of an exemplary cellular network100 which is used to help describe how a core network node 102 (e.g.,SGSN 102), multiple BSSs 104 ₁, 104 ₂ . . . 104 _(n), and a mobilestation 106 are configured to implement paging cycles with a longerduration than in the past in accordance with different embodiments ofthe present invention. The exemplary cellular network 100 comprises atleast the core network node 102 (e.g., SGSN 102) which interfaces with aHLR 108 and the multiple BSSs 104 ₁, 104 ₂ . . . 104 _(n). In thisexample, the BSS 104 ₁ manages cells 110 _(1a), 110 _(1b) . . . 110_(1x). The BSS 104 ₂ manages cells 110 _(2a), 110 _(2b) . . . 110 _(2x).The BSS 104 _(n) manages cells 110 _(na), 110 _(nb) . . . 110 _(nx). Inthis example, only one mobile station 106 has been shown which islocated in cell 110 _(1b) and is being serviced by BSS 104 ₁. However,it should be appreciated that any number of mobile stations 106 can besupported and can be located in one or more of the cells 110 _(1a), 110_(1b) . . . 110 _(1x), 110 _(2a), 110 _(2b) . . . 110 _(2x), and 110_(na), 110 _(nb) . . . 110 _(nx)). Further, it should be appreciatedthat the cellular network 100, the core network node 102 (e.g., SGSN102), the BSSs 104 ₁, 104 ₂ . . . 104 _(n), the mobile station 106 etc.. . . all contain components and have functionalities which are wellknown in the field, but for clarity, only those components andfunctionalities which are needed to explain and enable the disclosedtechniques which have been described herein. A detailed discussionregarding the basic concepts of the disclosed novel techniques isprovided next and then a detailed discussion is provided with respect toFIGS. 2-6 to explain how the mobile station 106, the BSSs 104 ₁, 104 ₂ .. . 104 _(n), and the core network node 102 (e.g., the SGSN 102) areconfigured to implement paging cycles which have a longer duration thanin the past in accordance with possible different embodiments.

In regards to the basic concept, a longer paging cycle (long DRX mode)is introduced for MSs 106 (e.g., MTC devices 106) which are used forless time critical communications to primarily save the battery power ofthose MSs 106. These MSs 106 would be identified by the core networknode 102 at registration (e.g., based on information included inregistration related NAS signaling or based on subscription informationmaintained by the HLR 108), such that the core network node 102 is awareof the device type and the presently set DRX period (i.e., paging cycle)for those MSs 106. Further, the core network node 102 takes appropriateactions whenever downlink payload 112 becomes available for a specificone of these MSs 106 and transmits to the set of BSSs 104 ₁, 104 ₂ . . .104 _(n), which are managing cells 110 _(1a), 110 _(1b) . . . 110 _(1x),110 _(2a), 110 _(2b) . . . 110 _(2x), and 110 _(na), 110 _(nb) . . . 110_(nx) in the applicable paging area 113 for the specific MS 106, amessage 111 containing information needed by the BSSs 104 ₁, 104 ₂ . . .104 _(n), to generate and transmit on a radio interface a radio block114 (e.g., paging block 114, paging message 114, paging notification114, CCCH block 114) for the mobile station 106.

The MS 106, while in idle mode, wakes periodically and performs thenecessary tasks specific for idle mode including checking for receipt ofthe radio block 114 and then returns to sleep mode. In the sleep mode,the MS 106 cuts the clock to most of its modules and thereby operates ina power saving mode. The longer the sleeping period, the more the poweris saved. Hence, to maximize the power saved by the MS 106 during thepower saving mode, the preferred option would be to prolong the sleepduration (e.g., increase the time between consecutive instances ofwaking up to perform the idle mode tasks). The disclosed techniquesperform this functionality.

To appreciate the benefits of the present invention, one should realizethat the traditional MS once it has camped to a suitable serving cellwould perform the following steps:

(1) Read BCCH information for BA list: MS reads BCCH to get neighborcell list.

(2) Make RSSI measurements for the neighbor cells identified using step(1).

(3) BSIC Identification: read FCCH and SCH of the cells in the cell database (neighbor+serving) to identify the cell-ID. If a new cell is found,it is added to the cell data base for periodic monitoring.

(4) BSIC reconfirmation: re-confirms cell-ID of the already detectedneighbor and serving cells by reading SCH.

(5) Cell reselection: camp to the best detected neighbor cell

(6) LA/RA update: perform NAS procedures for updating the LA and RA asneeded.

(7) AFC: does the frequency correction of the local clock.

All these tasks put a significant burden on the traditional MS in idlemode that leads to significant power consumption in order to keep thetraditional MS synchronized with the network for receiving pagingmessages in a time critical manner. The present disclosed techniquesreduce this overhead by eliminating the execution of the above tasks ona periodic basis and instead having the MS 106 executing them on an asneeded basis. In particular, this overhead is reduced by configuring theMS 106 such that, while it is in idle mode, there is no periodic RSSImeasurement, no background neighbor cell search, no BA list reading(e.g., no BCCH reading every 30 seconds), and no SCH reading for BSICreconfirmation every 30 seconds. Instead, the MS 106 is configured toimplement the procedure as described in detail below with respect toFIGS. 2-4.

Referring to FIG. 2, there is a flow chart of a method 200 in the mobilestation 106 (e.g., MTC device 106) for implementing paging cycles with alonger duration than in the past in accordance with the disclosedtechniques. The mobile station 106 comprises at least one processor 116and at least one memory 118 that stores processor-executableinstructions, wherein the at least one processor 116 interfaces with theat least one memory 118 to execute the processor-executable instructionssuch that the mobile station 106 is operable at step 202 to determine ifa serving cell 110 _(1b) (for example) is acceptable to stay camped-on.Further discussion is provided below on different ways that the mobilestation 106 can perform step 202. If the mobile station 106 determinesthat the serving cell 110 _(1b) is acceptable to stay camped-on, then atstep 204, the mobile station 106 performs (step 204 a) a first type ofsynchronizing procedure (i.e., short synchronizing procedure) and thenattempts (step 204 b) to read a radio block 114 (e.g., paging block 114,CCCH block 114, paging message 114, paging notification 114) receivedper a first DRX mode (i.e., long DRX mode), The first DRX mode has alonger time period than a legacy second DRX mode. If the mobile station106 is able to read the received radio block 114, then at step 206, themobile station 106 then (1) performs an action (step 206 a) based oncontent in the received radio block 114, (2) schedules (step 206 b) anext wake-up time based on the first DRX mode (i.e., long DRX mode) toperform the determination of step 202, and then (3) enters (step 206 c)sleep mode. If the mobile station 106 determines that the serving cell110 _(1b) is not acceptable to stay camped-on during step 202 or if themobile station 106 is not able to read the received radio block 114during step 204 b, the mobile station 106 schedules its next wakeupaccording to the first DRX mode (i.e., long DRX mode) then proceeds tostep 208, wherein the mobile station 106 performs (step 208 a) a secondtype of synchronizing procedure (i.e., long synchronizing procedure) andattempts (step 208 b) to read another radio block 114 a (e.g., anotherCCCH block 114 a). If the mobile station 106 is able to read the anotherreceived radio block 114 a during step 208 b, then at step 210, themobile station 106 then (1) performs an action (step 210 a) based oncontent in the another received radio block 114 a, (2) schedules (step210 b) a next wake-up time based on the first DRX mode to perform thedetermination of step 202, and then (3) enters (step 210 c) sleep mode.If the mobile station 106 is not able to read the another received radioblock 114 a during step 208 b, then at step 212, the mobile station 106(1) schedules (step 212 a) a next wake-up time based on the first DRXmode to perform the second type of synchronizing procedure and then (2)enters (step 212 b) sleep mode. Detailed descriptions of two exemplaryembodiments of method 200 are described next with respect to FIGS. 3 and4.

Referring to FIG. 3, there is a flow chart of a method 300 in the mobilestation 106 (e.g., MTC device 106) for implementing paging cycles with alonger duration than in the past in accordance with an embodiment. Themobile station 106 comprises at least one processor 116 and at least onememory 118 that stores processor-executable instructions, wherein the atleast one processor 116 interfaces with the at least one memory 118 toexecute the processor-executable instructions such that the mobilestation 106 is operable at step 302 to determine if a serving cell 110_(1b) (for example) is acceptable to stay camped-on. For example, themobile station 106 can perform step 302 as follows: (1) wake-up (step302 a) a predetermined first time (e.g., five slots before DRX cyclewake-up time) before a start time of a paging cycle based on the firstDRX mode, which has a longer time period than a legacy second DRX mode;(2) tune (step 302 b) to a radio frequency of a beacon channel of theserving cell 110 _(1b) and measure a RSSI of the beacon channel from theserving cell 110 _(1b); and (3) compare (step 302 c) the RSSI to athreshold value. If the RSSI is greater than the threshold value, thenthe serving cell 110 _(1b) is acceptable to stay camped-on. Otherwise,if the RSSI is less than the threshold value, then the serving cell 110_(1b) is not acceptable to stay camped-on.

If the mobile station 106 determines that the serving cell 110 _(1b) isacceptable to stay camped-on, then at step 304, the mobile station 106performs a first type of synchronizing procedure (i.e., shortsynchronizing procedure). For example, the mobile station 106 canperform the first type of synchronizing procedure as follows: (1) read(304 a) a predetermined number of bursts from a received beacon channelof the serving cell 110 _(1b); (2) search (304 b) for a TrainingSequence Code (TSC) in the read bursts to confirm cell identification ofthe serving cell 110 _(1b); (3) perform (304 c) Automatic FrequencyControl (AFC) operations and Automatic Time Control (ATC) operations;and (4) schedule (304 d) for reception of the radio block 114. Afterstep 304, the mobile station 106 performs step 306 and attempts to readthe radio block 114 (e.g., CCCH block 114). If the mobile station 106 isable to read the received radio block 114 (e.g., able to decode theradio block 114 and CRC passes), then at step 306 a, the mobile station106 then (1) performs an action based on content in the received radioblock 114 (e.g., passes the data to a higher layer), (2) schedules anext wake-up time based on the first DRX mode (i.e., long DRX mode) toperform the determination of step 302, and then (3) enters sleep mode.If the mobile station 106 is not able to read the received radio block114 (e.g., not able to decode the radio block 114 or the CRC does notpass), then at step 306 b, the mobile station 106 then schedules thesecond type of synchronizing procedure (i.e., long synchronizingprocedure) to perform the full cell search procedure before gettingready for the radio block reading (i.e., CCCH reading) in the next timeDRX wake-up period based on the first DRX mode, and then enters sleepmode.

If the mobile station 106 determines that the serving cell 110 _(1b) isnot acceptable to stay camped-on during step 302 (FIG. 3's numeral “A”which indicates the connection between step 302 c and step 308) or ifthe mobile station 106 is not able to read the received radio block 114during step 306, then at step 308, the mobile station 106 wakes-up apredetermined second time (e.g., 3 to 5 seconds before the DRX cyclewake-up time) before a start time of a next paging cycle based on thefirst DRX mode to perform, at step 310, the second type of synchronizingprocedure. For example, the mobile station 106 can perform the secondtype of synchronizing procedure as follows: (1) perform (step 310 a)Received Signal Strength Indicator (RSSI) measurement for differentfrequencies; (2) perform (step 310 b) Frequency Correction Channel(FCCH) search; (3) perform (step 310 c) Synchronization Channel (SCH)search; and (4) read (step 310 d) Broadcast Control Channel (BCCH)information. After step 310, the mobile station 106 at step 312 attemptsto read another radio block 114 a (e.g., another CCCH block 114 a). Ifthe mobile station 106 is able to read the another received radio block114 a (e.g., decode the radio block 114 a and CRC passes), then at step312 a, the mobile station 106 then (1) performs an action based oncontent in the another received radio block 114 a (e.g., passes the datato a higher layer), (2) schedules a next wake-up time based on the firstDRX mode to perform the determination of step 302, and then (3) enterssleep mode. If the mobile station 106 is not able to read (e.g., notable to decode the another radio block 114 a or the CRC does not pass)the received radio block 114 then proceed to step 312 b, wherein themobile station 106 then schedules the second type of synchronizingprocedure (i.e., long synchronizing procedure) to perform the full cellsearch procedure before getting ready for another radio block reading(e.g., CCCH reading) in the next time DRX wake-up period based on thefirst DRX mode, and then enters sleep mode. The method 300 is furtherdescribed next.

Once the long DRX period is set, the mobile station 106 will only wakeup, e.g., 5 slots earlier than its nominal long DRX paging block 114(determined according to the actual long DRX wakeup time) is scheduledto be received from its serving cell 110 _(1b) (for example) in order toperform some limited initial check and sync up operations, asillustrated in steps 302 and 302 a. The mobile station 106 will therebyverify whether it is already in-sync with the same serving cell 110_(1b) the mobile station 106 was camping on when it last successfullyperformed these limited operations. When the limited operations areperformed, the serving cell 110 _(1b) might not actually be the bestcell at that point, but if the mobile station 106 is still synchronizedwith the serving cell 110 _(1b), then the mobile station 106 willproceed. The steps corresponding to these limited operations are asbelow:

-   -   (1) Tune to the radio frequency (RF) of the serving cell's        beacon frequency and measure RSSI thereon (step 302 b).    -   (2) Compare and determine whether the RSSI of the serving cell        110 _(1b) is still higher than a threshold or not (step 302 c).    -   (3) If the result of step (2) is yes, that indicates that the        mobile station 106 can continue with its current serving cell        110 ₁₁₁ and perform the following:        -   a. Perform a short sync up procedure, where the mobile            station 106 will search the TSC number in any received            normal burst (i.e., to confirm the cell ID has not changed            since the last time the mobile station 106 successfully            performed the limited set of operations) (steps 304 a and            304 b), perform the frequency and time correction (step 304            c), then schedule the CCCH reading (i.e., the mobile station            106 schedules the reading of its nominal paging block 114            determined according to the long DRX mode)(step 304 d).        -   b. If the CCCH reading 306 a is successful (i.e., a valid            radio block 114 is read), then the mobile station 106 acts            accordingly and goes to sleep again after scheduling its            next wakeup according to the long DRX mode wherein the            mobile station 106 will wake up a few timeslots (TSs) early            (e.g. 5 TSs) to perform the limited initial check and sync            up operations (steps 302 and 304). Else if unsuccessful            (i.e., a valid radio block 114 is not read), then the mobile            station 106 schedules its next wakeup according to the long            DRX mode, but the mobile station 106 will wake up much            earlier (e.g., 3 to 5 seconds) before its nominal long DRX            paging block 114 is scheduled to be received in order to            perform the initial cell search method (i.e., what is            normally executed after the mobile station powers ON) (steps            306 b, 308 and 310). That means that the mobile station 106            will scan through the frequencies and, according to the            measured strongest RSSI (step 310 a), detect FCCH and SCH            (steps 310 b and 310 c), and perform the proper (i.e., full)            cell selection operations. The mobile station 106 will            perform all these steps before its nominal long DRX paging            block 114 is scheduled to be received, because the mobile            station 106 has awakened 3-5 seconds earlier than its            nominal long DRX period. Then, the mobile station 106            schedules the CCCH reading (i.e., paging block 114 reading)            and this time there is a high possibility that the CCCH            reading will pass (i.e., be successful) (step 312). If the            CCCH reading passes, then the mobile station 106 will go to            sleep according to the long DRX mode and when it next wakes            up, the mobile station 106 will only perform the limited            initial check and sync up operations (steps 302 and 304),            else the mobile station 106 will again schedule its next            wakeup according to the long DRX mode but the mobile station            106 will wake up much earlier (e.g., 3 to 5 seconds) before            its nominal long DRX paging block 114 is scheduled to be            received in order to perform the initial cell search method,            as illustrated in steps 312 b, 308 and 310.    -   (4) If the result of step (2) is no, that means that the present        cell 110 _(1b) is not suitable for signal reception, in which        case the mobile station 106 schedules its next wake-up according        to the long DRX mode but will wake up much earlier (e.g., 3 to 5        seconds) before its nominal long DRX paging block 114 is        scheduled to be received in order to perform the initial cell        search method (i.e., long sync up procedure) as discussed above        in step 3 b, as illustrated in steps 302, 308, 310 and 312.

As an alternative option, to allow the mobile station 106 to still havea chance to receive a radio block 114 (e.g., paging block 114, CCCHblock 114, paging message 114, paging notification 114) the BSS 104 ₁(for example) might have transmitted to the mobile station 106 using thenominal long DRX block if the result of step (2) is no, then the mobilestation 106 could operate in a manner that is described next withrespect to FIG. 4.

Referring to FIG. 4, there is a flow chart of a method 400 in the mobilestation 106 (e.g., MTC device 106) for implementing paging cycles with alonger duration than in the past in accordance with another embodiment.The mobile station 106 comprises at least one processor 116 and at leastone memory 118 that stores processor-executable instructions, whereinthe at least one processor 116 interfaces with the at least one memory118 to execute the processor-executable instructions such that themobile station 106 is operable at step 402 to determine if a servingcell 110 _(1b) (for example) is acceptable to stay camped-on. Forexample, the mobile station 106 can perform step 402 as follows: (1)wake-up (step 402 a) a predetermined first time (e.g., five slots beforeLONG DRX cycle wake-up time) before a start time of a paging cycle basedon the first DRX mode, which has a longer time period than a legacysecond DRX mode; (2) tune (step 402 b) to a radio frequency of a beaconchannel of the serving cell 110 _(1b) and measure a RSSI of the beaconchannel from the serving cell 110 _(1b); and (3) compare (step 402 c)the RSSI to a threshold value. If the RSSI is greater than the thresholdvalue then the serving cell 110 _(1b) is acceptable to stay camped-on.Otherwise, if the RSSI is less than or equal to the threshold value thenthe serving cell 110 _(1b) is not acceptable to stay camped-on.

If the mobile station 106 determines that the serving cell 110 _(1b) isacceptable to stay camped-on, then at step 404, the mobile station 106performs a first type of synchronizing procedure (i.e., shortsynchronizing procedure). For example, the mobile station 106 canperform the first type of synchronizing procedure as follows: (1) read(step 404 a) a predetermined number of bursts from a received beaconchannel of the serving cell 110 _(1b); (2) search (step 404 b) for aTraining Sequence Code (TSC) in the read bursts to confirm cellidentification of the serving cell 110 _(1b); (3) perform (step 404 c)Automatic Frequency Control (AFC) operations and Automatic Time Control(ATC) operations; and (4) schedule (step 404 d) for reception of theradio block 114. After step 404, the mobile station 106 performs step406 and attempts to read the radio block 114 (e.g., CCCH block 114). Ifthe mobile station 106 is able to read the received radio block 114(e.g., able to decode the radio block 114 and CRC passes), then at step406 a, the mobile station 106 then (1) performs an action based oncontent in the received radio block 114 (e.g., passes the data to ahigher layer), (2) schedules a next wake-up time based on the first DRXmode (i.e., long DRX mode) to perform the determination of step 402, andthen (3) enters sleep mode. If the mobile station 106 is not able toread the received radio block 114 (e.g., not able to decode the radioblock 114 or the CRC does not pass), then at step 406 b, the mobilestation 106 immediately performs the second type of synchronizingprocedure (i.e., long synchronizing procedure).

If the mobile station 106 determines that the serving cell 110 _(1b) isnot acceptable to stay camped-on during step 402 (FIG. 4's numeral “B”which indicates the connection between step 402 c and step 408) or ifthe mobile station 106 is not able to read the received radio block 114during step 406, then at step 408, the mobile station 106 immediatelyperforms the second type of synchronizing procedure and therebydiscovers a new serving cell 110 _(1a) (for example). For example, themobile station 106 can perform the second type of synchronizingprocedure as follows: (1) perform (step 408 a) Received Signal StrengthIndicator (RSSI) measurement for different frequencies; (2) perform(step 408 b) Frequency Correction Channel (FCCH) search; (3) perform(step 408 c) Synchronization Channel (SCH) search; and (4) read (step408 d) Broadcast Control Channel (BCCH) information. After step 408, themobile station 106 at step 410 schedules readings of up to N radioblocks 114 (e.g., CCCH blocks 114) in the new serving cell 110 _(1a)(for example) to be received per the legacy second DRX mode, whereinN>1. If one of the N radio blocks 114 is successfully read (step 410 a),then the mobile station 106 will (1) perform an action based on contentof the read one of the N radio blocks, (2) schedule a next wake-up timebased on the first DRX mode to perform the determination of step 402,and then (3) enter sleep mode. Otherwise, if none of the N radio blocks114 is successfully read (step 410 b), then the mobile station 106 will(1) schedule a next wake-up time based on the first DRX mode to performthe second type of synchronizing operation (step 408), and then (2)enter sleep mode. The method 400 is further described next.

Once the long DRX period is set, the mobile station 106 will only wakeup, e.g., 5 slots earlier than its nominal long DRX paging block 114(determined according to the actual long DRX wakeup time) is scheduledto be received from its serving cell 110 _(1b) (for example) in order toperform some limited initial check and sync up operations, asillustrated in steps 402 and 402 a. The mobile station 106 will therebyverify whether it is already in-sync with the same serving cell 110_(1b) it was camping on when it last successfully performed theselimited operations. When the limited operations are performed, theserving cell 110 _(1b) might not actually be the best cell at thatpoint, but if the mobile station 106 is still synchronized with theserving cell 110 _(1b), then the mobile station 106 will proceed. Thesteps corresponding to these limited operations are as below:

-   -   (1) Tune to the RF of the serving cell's beacon frequency and        measure RSSI thereon (step 402 b).    -   (2) Compare and determine whether the RSSI of the serving cell        110 _(1b) is still higher than a threshold or not (step 402 c).    -   (3) If the result of step (2) is yes, that indicates the mobile        station 106 can continue with its current serving cell 110 _(1b)        and perform the following:        -   a. Perform a short sync up procedure, where the mobile            station 106 will search the TSC number in any received            normal burst (i.e., to confirm the cell ID has not changed            since the last time the mobile station 106 successfully            performed the limited set of operations) (steps 404 a and            404 b), perform the frequency and time correction (step 404            c), then schedule the CCCH reading (i.e., the mobile station            106 schedules the reading of its nominal paging block 114            determined according to the long DRX mode)(step 404 d).        -   b. If the CCCH reading is successful (i.e., a valid radio            block 114 is read), then the mobile station 106 acts            accordingly and goes to sleep again after scheduling its            next wakeup according to the long DRX mode, wherein the            mobile station 106 will wake up a few TSs early (e.g., 5            TSs) to perform the limited initial check and sync up            operations (steps 402 and 404).    -   4. If the CCCH reading of step 3 a is unsuccessful (i.e., a        valid radio block 114 is not read) or if the result of step (2)        is no, which means that the present cell 110 _(1b) is not        suitable for signal reception, then the mobile station 106 could        proceed to (1) immediately perform the initial cell search        method (i.e., second synchronization procedure, long        synchronization procedure)(step 408) and thereby discover a new        serving cell 110 _(1a) (for example), and (2) then schedule the        reading up to N paging blocks 114 in the new serving cell 110        _(1a), for example, determined according to its short DRX mode        (i.e., legacy DRX mode) on the CCCH where N can have a default        value (e.g., 2) or be transmitted as part of system information        on the BCH of the new serving cell 110 _(1a) (step 410).

This means that each BSS 104 ₁, 104 ₂ . . . 104 _(n) which is managingcells 110 _(1a), 110 _(1b) . . . 110 _(1x), 110 _(2a), 110 _(2b) . . .110 _(2x), and 110 _(na), 110 _(nb) . . . 110 _(nx) in the applicablepaging area 113 will, after transmitting an initial page 114 (e.g.,radio block 114, CCCH block 114) according to the long DRX mode in eachcell 110 _(1a), 110 _(1b) . . . 110 _(1x), 110 _(2a), 110 _(2b) . . .110 _(2x), and 110 _(na), 110 _(nb) . . . 110 _(nx) of the paging area113, and determining that a corresponding page response 115 was notreceived, then repeat the transmitting of the page 114 up to ‘N’ timesin each of these cells 110 _(1a), 110 _(1b) . . . 110 _(1x), 110 _(2a),110 _(2b) . . . 110 _(2x), and 110 _(na), 110 _(nb) . . . 110 _(nx)according to the short DRX mode starting ‘X’ seconds after determiningthat the BSS 104 did not receive a page response 115 for the initialpage 114, where ‘X’ reflects the amount of time the mobile station 106needs to perform the initial cell search method (i.e., secondsynchronization procedure, long synchronization procedure. A detaileddescription about the BSS 104 ₁ (for example) performing this particularfunctionality is described below with respect to FIG. 5's steps 502, 504and 512 (i.e., labeled “alternative embodiment”).

5. After scheduling and successfully reading a radio block 114 in one ofthe up to ‘N’ nominal short DRX mode paging blocks 114, the mobilestation 106 will act on the content of that radio block 114 accordinglyand then go to sleep again after scheduling its next wakeup according tothe long DRX mode (step 410 a). Otherwise, the mobile station 106schedules its next wakeup according to the long DRX mode (step 410 b)but will wake up much earlier (e.g., 3 to 5 seconds) before its nominallong DRX paging block and perform the initial cell search method (i.e.,second synchronization procedure, long synchronization procedure) againas described above with respect to step 408.

It should be appreciated that the number of short DRX mode paging blocks114 being transmitted between two long DRX mode paging blocks 114 isexpected to be quite large, which means that even if, e.g., the mobilestation 106 reads three or four short DRX mode paging blocks 114 in thenew serving cell 110 _(1a) (for example), it will still represent adramatic reduction in the total number of paging blocks 114 readcompared to what the mobile station 106 would have read over the timeperiod spanned by a long DRX mode cycle using legacy DRX mode. Thisrepeated transmission of paging blocks over a short interval (defined bythe legacy DRX mode) after the long DRX paging cycle helps the mobilestation 106 to successfully decode the paging message 114 it was unableto read within its nominal paging block. When long DRX is employed inthe system, then the paging cycle will be very long. Thus, in such case,if the mobile station 106 (i.e., device) misses the paging messagetransmitted within its nominal paging block 114, then ideally the mobilestation 106 has to wait for a long time (e.g., 1 hour or so, based onthe long DRX period) to get the next paging message. As such, by readingone or more paging blocks 114 over a short interval (defined by thelegacy DRX mode) occurring after its nominal paging block 114, themobile station 106 (i.e., device) need not have to wait for the nextpaging block occurring according to its long DRX cycle.

In addition, it should be appreciated that how much time the mobilestation 106 needs to perform the initial cell search method (i.e.,second synchronization procedure, long synchronization procedure) willdetermine how long the BSS 104 ₁, 104 ₂ . . . 104 _(n) should wait afterit determines that it has not received a response 115 to the initialpage 114 and begins transmitting up to ‘N’ repeats of the initial page114 according to the short DRX mode. Furthermore, if performing theinitial cell search method (i.e., second synchronization procedure, longsynchronization procedure) results in the mobile station 106 winding upin a different routing area, then it may also mean the mobile station106 has moved to a different paging area, in which case the mobilestation 106 will not receive any of the up to ‘N’ repeated pages 114,but this should not occur very often.

In view of the foregoing discussions with respect to FIGS. 2-4, oneskilled in the art will appreciate that the present invention canutilize two configurations—long and short DRX modes, wherein the longDRX mode is the new inventive mode, while the short DRX mode is thelegacy mode. There could be several different options for theconfiguration switching between long and short DRX modes, for examplesome options are described as below:

1. For long DRX capable devices, the core network node 102 could changethe paging repetitions and duration in case the paging response 115 isnot received after X amount of time.

2. In case the mobile station 106 loses synchronization while reading apaging message 114 (radio block 114), the mobile station 106 could (a)transmit an indication 117 to core network node 102 indicating thenon-reception of paging message 114, and when the core network node 102received this indication, then the core network node 102 could quicklytransmit to the BSS 104 ₁ (for example) a message containing informationthat the BSS 104 ₁ needs to generate and transmit on the radio interfacea radio block containing the paging message 114, or (b) transmit anindication to the BSS 104 ₁ (for example), which would normally keep thepaging message 114 for a little longer time than the BSS 104 ₁ would forthe non-long DRX capable devices (i.e., traditional mobile stations) sothat on reception of the special indication 117 from the mobile station106, then the BSS 104 ₁ could retransmit the page 114 instead ofinvolving core network node 102. A detailed description about the BSS104 ₁ (for example) performing this particular functionality isdescribed below with respect to FIG. 5's steps 502, 504, 506, and 510(i.e., labeled “one embodiment”).

3. The BSS 104 ₁ (for example) keeps track (e.g., maintains a record) ofthe paging messages 114 for the mobile station 106 (i.e., long DRXcapable device 106) for a longer period of time than the BSS 104 ₁ keepstrack of a radio block (paging message) broadcast to a traditionalmobile station (i.e., non-long DRX capable device). In addition, the BSS104 ₁ after transmitting the paging message 114, keeps track to see if apaging response 115 is received from the particular mobile station 106.If the BSS 104 ₁ does not receive the paging response 115 from themobile station 106 after X amount of time, then the BSS 104 ₁ canretransmit the page message 114 by itself without involving the corenetwork node 102 (e.g., SGSN 102). A detailed description about the BSS104 ₁ (for example) performing this particular functionality isdescribed below with respect to FIG. 5's steps 502, 504, 506, and 508(i.e., labeled “one embodiment”).

Referring to FIG. 5, there is a flow chart of a method 500 in the BSS104 ₁ (for example) for implementing paging cycles with a longerduration than in the past in accordance with the different embodiments.The BSS 104 ₁ comprises at least one processor 120 and at least onememory 122 that stores processor-executable instructions, wherein the atleast one processor 120 interfaces with the at least one memory 122 toexecute the processor-executable instructions such that the BSS 104 ₁ isoperable at step 502 to receive, from the core network node 102, amessage 111 containing information the BSS 104 ₁ needs to generate andtransmit one radio interface a radio block 114 (e.g., paging block 114,CCCH block 114, paging message 114, paging notification 114) for mobilestation 106 (see also FIG. 1). The BSS 104 ₁ is further operable at step504 to transmit (broadcast) the radio block 114 according to a first DRXmode rather than a legacy second DRX mode in one or more cells 110_(1a), 110 _(1b) . . . 110 _(1x) of the paging area 113 of the mobilestation 106, wherein the first DRX mode has a longer time period thanthe legacy second DRX mode. According to the labeled “one embodiment”section in the flowchart, the BSS 104 ₁ after step 504 is operable perstep 506 to keep track of the radio block 114 transmitted according tothe first DRX mode to the mobile station 106 longer than the BSS 104 ₁keeps track of a radio block transmitted to another mobile station(i.e., non-long DRX capable mobile station) according to the legacysecond DRX mode. Then, the BSS 104 ₁ at step 508, upon determining thata paging response 115 was not received from the mobile station 106, willafter a predetermined time retransmit the radio block 114 to the mobilestation 106 without involving the core network node 102. The steps 502,504, 506, 508 and 510 correspond with the mobile station 106 operationdescribed above with respect to FIG. 3. Or, the BSS 104 ₁ at step 510,upon receiving an indication 117 from the mobile station 106 indicatingnon-reception of the radio block 114, will retransmit the radio block114 to the mobile station 106 without involving the core network node102. According to the labeled “alternative embodiment” section in theflowchart, the BSS 104 ₁ after step 504 is operable per step 512 suchthat the BSS 104 ₁, upon determining that a paging response 115 was notreceived from the mobile station 106, will after a predetermined timerepeatedly transmit the radio block 114 according to the legacy secondDRX mode up to N times in the one or more cells 110 _(1a), 110 _(1b) . .. 110 _(1x) of the paging area 113. The steps 502, 504 and 512correspond with the mobile station 106 operation described above withrespect to FIG. 4.

Referring to FIG. 6, there is a flow chart of a method 600 in the corenetwork node 102 for implementing paging cycles with a longer durationthan in the past in accordance with an embodiment. The core network node102 comprises at least one processor 124 and at least one memory 126that stores processor-executable instructions, wherein the at least oneprocessor 124 interfaces with the at least one memory 126 to execute theprocessor-executable instructions such that the core network node isoperable at step 602 to identify the mobile station 106 as beingconfigured per a first DRX mode rather than a legacy second DRX mode,wherein the first DRX mode has a longer time period than the legacysecond DRX mode. For example, the core network node 102 can identify themobile station 106 as being configured per a first DRX mode rather thana legacy second DRX mode based on (1) using (step 602 a) informationincluded in registration related Non Access Stratum (NAS) signaling, or(2) using (step 602 b) subscription information associated with themobile station 106, wherein the core network node 102 can obtain thesubscription information from the HLR 108. At step 604, the core networknode 102 is operable to receive the downlink payload 112 for the mobilestation 106. Upon receipt of the downlink payload 112, the core networknode 102 performs step 606 and transmits to the BSSs 104 ₁, 104 ₂ . . .104 _(n) which manage cells 110 _(1a), 110 _(1b) . . . 110 _(1x), 110_(2a), 110 _(2b) . . . 110 _(2x), and 110 _(na), 110 _(nb) . . . 110_(nx) in the paging area 113 of the mobile station 106, a message 111containing information needed to generate and transmit on a radiointerface a radio block 114 (e.g., paging block 114, CCCH block 114,paging message 114, paging notification 114) for mobile station 106 perthe first DRX mode. After step 606, the core network node 102 performsstep 608 and changes the duration (periodicity) of transmitting messages111 to the BSSs 104 ₁, 104 ₂ . . . 104 _(n) that result in thetransmission of radio blocks 114 for the mobile station 106) when apaging response 115 is not received from the mobile station 106 during apredetermined amount of time. Or, the core network node 102 after step606 can perform step 610 wherein, upon receiving an indication 117 fromthe mobile station 106 indicating the non-reception of the radio block114, the core network node 102 retransmits a message 111 to the BSSs 104₁, 104 ₂ . . . 104 _(n) that results in the transmission of the radioblock 114 for the mobile station 106. The mobile station 106 cantransmit the indication 117 when the mobile station 106 has received theradio block 114 but lost synchronization such that the mobile station106 could not finish decoding the radio block 114.

One skilled in the art should appreciate that the disclosed techniquesresult in a large power savings gain for the mobile station 106. Forexample, if the legacy DRX cycle is 10 minutes and the new long DRXcycle is 1000 minutes and the observation period for battery energysaving in the mobile station 106 is three days (i.e., the normal batteryback time), then it was found that the energy saving ratio will bealmost three thousand times. The detailed computation is provided belowin TABLE #1.

TABLE 1 Power Power Power Power Power Power Probability consumptionconsumption consumption consumption consumption consumption of 1st foreach for each for each for RSSI for each for each BSIC CCCH fail = CCCHBSIC BA list reading for 8 short sync up reading = 40% = 0.4 reading =reading = reading = neighbor cells procedure = PC_long_sync PC_ccchPC_bsic PC_ba 5 times = PC_short_sync (uJ) = 10000 (uJ) = 400 (uJ) = 200(uJ) = 600 PC_rssi (uJ) = 30 (uJ) = 1000 Occurrence OccurrenceOccurrence Occurrence Occurrence Occurrence Occurrence of CCCH of BSICof BA in of short Sync of long sync of CCCH reading in reading inreading in observation in observation in observation reading inobservation observation observation period period period observationperiod period period period 4.32 [using 0 0 0 2.592 1.728 4.32 proposedLong DRX method with DRX cycle of 1000 min] 17280 [using 8640 8640 51840legacy DRX method with DRX cycle of 0.25 min] DRX Cycle Legacy (in min)= 0.25 min DRX Cycle New (in min) = 1000 min Observation Period = 3 days= 4320 min Power Consumption (mJ) Legacy 65664000 Power Consumption (mJ)New 19085.76 Power Saving Ratio (Legacy/New) 3440.470801

In normal scenarios, most of the time the mobile station 106 willperform the short synchronization process (i.e., short sync up) sincethe signal strength of the serving cell serving cell 110 _(1b) (forexample) does not change very frequently in normal operation. This willhelp to save (i.e., conserve) the battery power as the mobile station106 will avoid having to perform the idle mode tasks most of time. Thefollowing are some additional exemplary advantages of the disclosedtechniques:

(1) The mobile station 106 (and other similar devices 106) will stay fora long period of time in the sleep mode.

(2) Conventionally, a mobile station needs to wake up to perform severaltasks related to idle mode that are not required with the disclosedtechniques, in which the mobile station 106 will wake up only in the DRXcycle and do what is required as discussed above with respect to FIGS.2-4. This increases the sleep duration and that saves (i.e., conserves)the batter power of the mobile station 106.

(3) The power saving ratio between the traditional method and the newlyproposed method is very significant, as illustrated in TABLE #1.

(4) The mobile station 106 does not have to do the periodic RSSImeasurement, BSIC conf/re-conf, and BCCH reading according to a fixedminimum periodicity. Thus, there is no need for the mobile station 106to wake-up and perform periodic tasks according to a fixed minimumperiodicity and instead the mobile station 106 will only wake up at theDRX cycle. As such the duration of the DRX cycle could be anything asthe wake-up interval will, to a great extent, no longer be impacted orrestricted by the need to support fixed tasks requiring a minimumperiodicity of execution due to elimination of some idle mode cellre-selection related tasks and introduction of the short sync upprocedure.

(5) MTC devices 106 (or sensor type of devices) will be helped, wherebattery power conversation is especially important.

(6) The mobile station 106 continues to be able to receive an initialpage 114 that was missed on its nominal long DRX mode paging block byimmediately performing the initial cell search method following thedetection of an RRSI on the new serving cell 110 _(1a) (for example)(e.g., detected using the limited initial check and sync up operationsand determined to have a RSSI greater than a threshold) and then lookingfor up to N repeats of the initial page 114 using its short DRX mode inthe new serving cell 110 _(1a), as illustrated in FIG. 4. This may be ofimportance for the case where the delivery of payload 112, though nottime critical in general, should still be performed within the timeperiod spanned by a long DRX cycle, as this may be part of thecontracted quality of service for a given MTC application.

(7) The consumption of energy by the mobile station 106 is reduced whilein idle mode, which leads to a significant decrease in the rate thatbattery power of the mobile station 106 is drained.

The aforementioned mobile station 106, the core network node 102, theBSSs 104 ₁, 104 ₂ . . . 104 _(n), and various methods 200, 300 and 400of the present invention can also have one or more of the followingfeatures:

1. A method to reduce power usage in a terminal or mobile station 106,comprising performing wake-up and synchronization operations accordingto a long DRX period.

1A. The method of feature 1, further comprising on every wakeup from DRXsleep mode, the mobile station 106 verifies whether it is alreadyconnected to an earlier camped cell or if it has moved, by firstmeasuring the received signal strength indication (RSSI) of thepreviously camped cell and comparing it with a threshold value.

1B. The method of feature 1A, wherein if the RSSI of the previouslycamped cell is greater than a threshold, the mobile station 106 assumesthat it is still connected to the earlier cell and, based on the result,the mobile station 106 determines whether to perform a short sync up ora long sync up with a network.

1C. The method of feature 1, wherein in a long DRX period, the periodicRSSI measurement, BSIC conf/re-conf, broadcast control channel (BCCH)reading, AFC and similar operations are delayed or deferred to reducebattery power.

2. A method of reducing battery usage in a mobile station 106,comprising performing a faster sync up wherein the mobile station 106reads any normal burst and performs the frequency synchronization, timesynchronization using known TSC data in the burst, and then prepares forCommon Control Channel (CCCH) reception, wherein this short sync uptakes few slots of time.

2A. The method of feature 2, wherein the mobile station 106 does notneed to wait for the frequency correction channel (FCCH).

3. A method of reducing battery usage in a mobile station 106,comprising performing a long sync up, wherein the mobile station 106performs the same operations as it did after powering on when CCCHdecoding fails or when a mobile station 106 has lost the prior cell, asdetected by the algorithm or process described herein.

Further, the cellular network 100 is shown and described herein as beingconfigured per the GSM standard, but it should be appreciated that thecellular network 100 and other components of the present invention canbe configured per UTRA, E-UTRA or any other radio access technologywherein the reachability of wireless devices 106 therein hashistorically been based on the assumption that all deliveries ofdownlink packet data payload requires a rather low latency in the areaof a few seconds. Finally, it should be appreciated that the presentinvention is not limited to mobile stations 106's that are characterizedas MTC devices but could be any type of device if desired.

Although multiple embodiments of the present invention have beenillustrated in the accompanying Drawings and described in the foregoingDetailed Description, it should be understood that the invention is notlimited to the disclosed embodiments, but instead is also capable ofnumerous rearrangements, modifications and substitutions withoutdeparting from the present invention that as has been set forth anddefined within the following claims.

The invention claimed is:
 1. A mobile station configured to implement paging cycles in a cellular network, the mobile station comprising: at least one processor; and, at least one memory that stores processor-executable instructions, wherein the at least one processor interfaces with the at least one memory to execute the processor-executable instructions, whereby said mobile station is operable to: determine whether a serving cell in the cellular network is acceptable to stay camped-on; based on a result of the determination that the serving cell is acceptable to stay camped-on, perform a first type of synchronizing procedure and attempt to read a radio block received per a first Discontinuous Reception (DRX) mode, wherein the first DRX mode has a longer time period than a legacy second DRX mode; and, based on a result of the determination that the serving cell is not acceptable to stay camped-on or the mobile station is not able to read the received radio block, perform a second type of synchronizing procedure and attempt to read another radio block, wherein the first type of synchronizing procedure has a shorter duration than the second type of synchronizing procedure.
 2. The mobile station of claim 1, wherein the mobile station is operable to: when the mobile station is able to read the received radio block, (1) perform an action based on content of the received radio block, (2) schedule a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) enter sleep mode.
 3. The mobile station of claim 1, wherein the mobile station is operable to: when the mobile station is able to read the another received radio block, (1) perform an action based on content of the another received radio block, (2) schedule a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) enter sleep mode; and when the mobile station is not able to read the another received radio block, (1) schedule a next wake-up time based on the first DRX mode to perform the second type of synchronizing procedure, and (2) enter sleep mode.
 4. The mobile station of claim 1, wherein the mobile station is operable to determine whether the serving cell is acceptable to stay camped-on by: waking-up a predetermined first time before a start time of a paging cycle based on the first DRX mode; tuning to a radio frequency of a beacon channel of the serving cell and measuring a Received Signal Strength Indicator (RSSI) of the beacon channel of the serving cell; and comparing the RSSI to a threshold value, wherein when the RSSI is greater than the threshold value then the result of the determination is that the serving cell is acceptable to stay camped-on, and when the RSSI is less than the threshold value then the result of the determination is that the serving cell is not acceptable to stay camped-on.
 5. The mobile station of claim 1, wherein the first type of synchronizing procedure comprises: reading a predetermined number of bursts from a received beacon channel of the serving cell; searching for a Training Sequence Code (TSC) in the read bursts to confirm cell identification of the serving cell; performing Automatic Frequency Control (AFC) operations and Automatic Time Control (ATC) operations; and scheduling for reception of the radio block.
 6. The mobile station of claim 1, wherein the mobile station is operable to: when a result of the determination is that the serving cell is not acceptable to stay camped-on or the mobile station is not able to read the received radio block, wake-up a predetermined second time before a start time of a next paging cycle based on the first DRX mode to perform the second type of synchronizing procedure.
 7. The mobile station of claim 1, wherein the second type of synchronizing procedure comprises: performing Received Signal Strength Indicator (RSSI) measurement for different frequencies; performing Frequency Correction Channel (FCCH) search; performing Synchronization Channel (SCH) search; and reading Broadcast Control Channel (BCCH) information.
 8. The mobile station of claim 1, wherein when a result of the determination is that the serving cell is not acceptable to stay camped-on then the mobile station is further operable to: immediately perform the second type of synchronizing procedure; schedule readings of up to N radio blocks to be received per the legacy second DRX mode, wherein N>1; and when one of the N radio blocks is successfully read, (1) perform an action based on content of the read one of the N radio blocks, (2) schedule a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) enter sleep mode; or when none of the N radio blocks is successfully read, (1) schedule a next wake-up time based on the first DRX mode to perform the second type of synchronizing procedure, and (2) enter sleep mode.
 9. The mobile station of claim 1, wherein the radio block is one of the following: a paging block, a Common Control Channel (CCCH) block, a paging message, or a paging notification.
 10. A method in a mobile station for implementing paging cycles in a cellular network, the method comprising: determining whether a serving cell in the cellular network is acceptable to stay camped-on; based on a result of the determination that the serving cell is acceptable to stay camped-on, performing a first type of synchronizing procedure and attempting to read a radio block received per a first Discontinuous Reception (DRX) mode, wherein the first DRX mode has a longer time period than a legacy second DRX mode; and, based on a result of the determination that the serving cell is not acceptable to stay camped-on or the mobile station is not able to read the received radio block, performing a second type of synchronizing procedure and attempting to read another radio block, wherein the first type of synchronizing procedure has a shorter duration than the second type of synchronizing procedure.
 11. The method of claim 10, wherein when the mobile station is able to read the received radio block then (1) performing an action based on content of the received radio block, (2) scheduling a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) entering sleep mode.
 12. The method of claim 10, wherein: when the mobile station is able to read the another received radio block, (1) performing an action based on content of the another received radio block, (2) scheduling a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) entering sleep mode; and when the mobile station is not able to read the another received radio block, (1) scheduling a next wake-up time based on the first DRX mode to perform the second type of synchronizing procedure, and (2) entering sleep mode.
 13. The method of claim 10, wherein the step of determining whether the serving cell is acceptable to stay camped-on comprises: waking-up a predetermined first time before a start time of a paging cycle based on the first DRX mode; tuning to a radio frequency of a beacon channel of the serving cell and measuring a Received Signal Strength Indicator (RSSI) of the beacon channel of the serving cell; and comparing the RSSI to a threshold value, wherein when the RSSI is greater than the threshold value then the result of the determination is that the serving cell is acceptable to stay camped-on, and when the RSSI is less than the threshold value then the result of the determination is that the serving cell is not acceptable to stay camped-on.
 14. The method of claim 10, wherein the first type of synchronizing procedure comprises: reading a predetermined number of bursts from a received beacon channel of the serving cell; searching for a Training Sequence Code (TSC) in the read bursts to confirm cell identification of the serving cell; performing Automatic Frequency Control (AFC) operations and Automatic Time Control (ATC) operations; and scheduling for reception of the radio block.
 15. The method of claim 10, wherein based on the result of the determination that the serving cell is not acceptable to stay camped-on or the mobile station is not able to read the radio block message, waking-up a predetermined second time before a start time of a next paging cycle based on the first DRX mode to perform the second type of synchronizing procedure.
 16. The method of claim 10, wherein the second type of synchronizing procedure comprises: performing Received Signal Strength Indicator (RSSI) measurement for different frequencies; performing Frequency Correction Channel (FCCH) search; performing Synchronization Channel (SCH) search; and reading Broadcast Control Channel (BCCH) information.
 17. The method of claim 10, wherein based on the result of the determination that the serving cell is not acceptable to stay camped-on: immediately performing the second type of synchronizing procedure; scheduling readings of up to N radio blocks to be received per the legacy second DRX mode, wherein N>1; and when one of the N radio blocks is successfully read, (1) performing an action based on content of the read one of the N radio blocks, (2) scheduling a next wake-up time based on the first DRX mode to determine whether the serving cell is acceptable to stay camped-on, and (3) entering sleep mode; or when none of the N radio blocks is successfully read, (1) scheduling a next wake-up time based on the first DRX mode to perform the second type of synchronizing procedure, and (2) entering sleep mode.
 18. The method of claim 10, wherein the radio block is one of the following: a paging block, a Common Control Channel (CCCH) block, a paging message, or a paging notification.
 19. A base station subsystem (BSS) configured to implement paging cycles for a mobile station in a cellular network, the BSS comprising: at least one processor; and, at least one memory that stores processor-executable instructions, wherein the at least one processor interfaces with the at least one memory to execute the processor-executable instructions, whereby said BSS is operable to: receive, from a core network node in the cellular network, a message containing information the BSS needs to generate and transmit on a radio interface a radio block for the mobile station; transmit the radio block according to a first Discontinuous Reception (DRX) mode rather than a legacy second DRX mode in one or more cells of a paging area of the mobile station, wherein the first DRX mode has a longer time period than the legacy second DRX mode; keep track of the radio block transmitted according to the first DRX mode to the mobile station longer than the BSS keeps track of a radio block transmitted to another mobile station according to the legacy second DRX mode; and upon determining that a paging response was not received from the mobile station after a predetermined time, retransmit the radio block to the mobile station without involving the core network node; or upon receiving an indication from the mobile station indicating non-reception of the radio block, retransmit the radio block to the mobile station without involving the core network node.
 20. The BSS of claim 19, further operable to: upon determining that a paging response was not received from the mobile station, after a predetermined time, repeatedly transmit the radio block up to N times in the one or more cells of the paging area, wherein the radio block is repeatedly transmitted up to N times according to a legacy second DRX mode.
 21. The BSS of claim 19, wherein the radio block is one of the following: a paging block, a Common Control Channel (CCCH) block, a paging message, or a paging notification.
 22. A method in a base station subsystem (BSS) for implementing paging cycles for a mobile station in a cellular network, the method comprising: receiving, from a core network node in the cellular network, a message containing the information the BSS needs to generate and transmit on a radio interface a radio block for the mobile station; transmitting the radio block according to a first Discontinuous Reception (DRX) mode rather than a legacy second DRX mode in one or more cells of a paging area of the mobile station, wherein the first DRX mode has a longer time period than the legacy second DRX mode; keeping track of the radio block transmitted according to the first DRX mode to the mobile station longer than the BSS keeps track of a radio block transmitted to another mobile station according to the legacy second DRX mode; and upon determining that a paging response was not received from the mobile station, after a predetermined time, retransmitting the radio block to the mobile station without involving the core network node; or upon receiving an indication from the mobile station indicating non-reception of the radio block, retransmitting the radio block to the mobile station without involving the core network node.
 23. The method of claim 22, further comprising: upon determining that a paging response was not received from the mobile station, after a predetermined time, repeatedly transmit the radio block up to N times in the one or more cells of the paging area, wherein the radio block is repeatedly transmitted up to N times according to a legacy second DRX mode.
 24. The method of claim 22, wherein the radio block is one of the following: a paging block, a Common Control Channel (CCCH) block, a paging message, or a paging notification. 